In recent years, in order to achieve a weight reduction of an automobile, weight reductions of various composing members have been challenged. Among them, the laminated glass to be used as an openable and closable window glass in an automobile door has also been required to be reduced in weight. Further, the laminated glass of the automobile door has been required to have a sound insulating property that allows blocking of wind noises and body vibration sounds during running conventionally. The laminated glass typically has a composition in which an interlayer film is sandwiched between a pair of glass plates, and as for the laminated glass for an automobile door, there has been known a technique of enhancing the sound insulating property by adjusting materials and a composition of the interlayer film (see Patent Reference 1 (JP-A 2000-272937), for example).
To reduce the thickness of the glass plate is considered to contribute to the weight reduction of the laminated glass, but it causes a significant concern that the thinner glass plate necessarily entails a reduced strength of the laminated glass. Thus, by increasing rigidity while maintaining a sound insulating property of the interlayer film, the sound insulating property, the weight reduction, and the strength maintenance of the laminated glass are tried to be achieved at the same time. However, use of a highly rigid interlayer film causes a phenomenon in which the sound insulating property deteriorates in a specific frequency region, to thus be a problem.